1. Field of the Invention
This invention relates to an improved construction for a medicine ball which makes the ball lighter, less expensive to manufacture, easier to throw and catch, and less likely to injure a person who is struck by the ball.
2. Description of the Prior Art
Conventional medicine balls are used to provide aerobic exercise to a person when the ball is thrown or caught. Most medicine balls are relatively heavy and have considerable mass in order to produce optimum expenditure of energy when the ball is in use. The mass is generally provided by surrounding a heavy object with a fibrous material such as loose cotton batting or wadded pieces of cloth. The outside of the ball is generally composed of sections of leather, cloth, rubber or plastic stitched together to forms a spherical covering about the heavy, padded central mass. The outside of the ball is soft and pliable so that it can be grasped more easily when being thrown or caught, and because of its pliable outside and soft cloth inside the ball will deform to a substantial degree when striking a person or object. The force of the impact will be distributed over a larger area than if the ball were firm, and risk of injury to persons or object is considerably reduced. However, because the mass of the ball is great, injuries to persons, especially younger persons or children, may result if the ball is improperly thrown or caught.
Conventional athletic balls such as footballs and basketballs are composed of an inflatable, high strength inner bladder, and an outer layer of heavy leather, rubber or plastic material. Such balls are inflated to high pressure and thrown, kicked or bounced, all of which can cause injuries to fingers as well as other parts of the body, and to property as well.
The present invention uniquely combines the pliability of a standard medicine ball with the ease of manufacture and sturdiness of an inflatable athletic ball to produce an improved medicine ball. The ball may be of any size, but is preferably about the size of a standard soccer ball. It has a sturdy leather or plastic cover and an inflatable inner bladder of sufficient thickness that, at relatively low inflation pressures, permits the ball to be lighter in weight than conventional medicine balls yet pliable so that it is easy to throw and catch, even for children. The lighter ball is less likely to cause injuries, but as with standard medicine balls should not be kicked or headed like a soccer ball.
In its construction the present improved medicine ball is substantially different from the inflatable play ball described in U.S. Pat. No. 4,484,382 to Spector in that the wall of the inflatable bladder of this invention is considerably thicker, adding mass and weight to the ball yet permitting the ball to be pliable when inflated to low pressures. The present invention is also different from the pliant soccer ball having a wound cotton interior as described in U.S. Pat. No. 4,542,902 to Massino, and from the soccer ball with a two-ply butyl floating bladder described in U.S. Pat. No. 4,830,373 to Dehnert et al. The bladder of the present invention does not float, but is secured to the inside of the covering.
It is therefore an object of this invention to provide a unique medicine ball which is smaller and lighter than conventional ball, but which is pliable and easily thrown and caught.
Another object of this invention is a novel construction for a medicine ball wherein the inside is an inflatable bladder with heavy, thick walls which add mass but which are pliable when inflated to low pressures.
A further object of this invention is a small, light weight medicine ball that is easy to construct and is less likely to cause injury.
A still further object of this invention is a novel medicine ball in which a thick-walled rubber bladder is secured about its valve seat to the inside of its covering.